document.write( "Question 93182: 1)Given the binary operation * defined over the set of real numbers R by a*b=a+b+ab. What are the invertible elements of R with respect to *.\r
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Algebra.Com's Answer #67810 by venugopalramana(3286)\"\" \"About 
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1)Given the binary operation * defined over the set of real numbers R by a*b=a+b+ab. What are the invertible elements of R with respect to *.\r
\n" ); document.write( "\n" ); document.write( "LET I BE THE IDENTITY ELEMENT WRT * OPERATION.SO
\n" ); document.write( "A*I=A=A+I+AI
\n" ); document.write( "I(A+1)=0
\n" ); document.write( "I=0
\n" ); document.write( "HENCE IF X IS INVERSE OF A THEN
\n" ); document.write( "A*X=I=0=A+X+AX
\n" ); document.write( "X(A+1)= -A
\n" ); document.write( "X=-A/(A+1)
\n" ); document.write( "HENCE A SHOULD NOT BE -1
\n" ); document.write( "SO ALL ELEMENTS IN R EXCEPT A=-1 ARE INVERTIBLE
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